This section introduces information from the art that may be related to or provide context for some aspects of the technique described herein and/or claimed below. As the section's title implies, this information is “background” facilitating a better understanding of that which is disclosed herein. This is a discussion of “related” art. That such art is related in no way implies that it is also “prior” art. The related art may or may not be prior art. The discussion is to be read in this light, and not as admissions of prior art.
One type of battery is known as a thermal battery. A thermal battery typically includes at least one cell. Frequently, they include several cells in a stack. The stack is disposed within a can. The normal manufacturing of a thermal battery utilizes a press and internal shims to set the can header to the right height to weld the case. The press pressurizes the stack to provide what is known as the “stack pressure” and the weld holds the pressure in the thermal battery until the unit is activated.
As a thermal battery is activated the internal stack pressure in the case drops significantly. This drop in pressure adversely effects the reaction which provides the electrical output for the battery. More particularly, thermal batteries with large numbers of cells have issues with holding the pressure on the stack of cells when the battery is activated. The cause of this pressure loss is that as the separator changes phase, it loses some of it volume. This volume loss results in a susceptibility of the stack to vibration and shock and causes a dropout in the voltage.
A variety of thermal battery designs are available to the art, many of which are competent for their intended purposes despite problems such as that discussed above. The art however is always receptive to improvements or alternative means, methods and configurations. Accordingly, the technique disclosed herein should be well received by the art.